JPH0326418Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention A-1. Field of Industrial Use This invention relates to a gas meter with a shutoff device that shuts off gas when the gas flow rate deviates from a specified range or in an emergency.

A-2 Conventional technology and its problems When indoor gas piping is used in an emergency such as an earthquake, a power outage, a leak of unburned gas, or when the gas flow rate is outside the specified range,
When it is necessary to automatically cut off the gas supply for safety reasons, conventionally, as in Japanese Patent Laid-Open No. 58-88617, a valve seat is installed at a part of the outlet of the upper case that has the gas inlet and outlet passage. A gas meter with a shutoff device is used, which is provided with a valve body driven by an electromagnet and constitutes a valve device that opens and closes a gas passage.

This device has a valve seat and a valve body dedicated to shutting off the gas, so it has the problem of a large number of parts and high costs.

Japanese Unexamined Patent Publication No. 56-27613 and Utility Model Application No. 57-179124
The idea in the publication focuses on the distribution switching valve that gas meters are originally equipped with, and fixes the drive mechanism that drives the switching valve by the movement of the metering membrane when necessary, stopping the switching valve from moving and cutting off the gas flow. This has the advantage of not requiring a valve seat and valve body exclusively for shutoff, unlike the prior art described above.Difference pressure acts on the metering membrane during shutoff, and this force acts on the shutoff mechanism and switching valve. Acts on all drive mechanisms. The differential pressure at this time must be assumed to be the maximum supply gas pressure, which is 10 to 15 times the value when using a normal gas meter.
The strength of the meter's drive mechanism had to be strengthened to withstand this, resulting in problems such as increased size, weight, and cost.

B. Structure of the invention B-1 Means for solving the problem Valve seat 19a has entrances and exits 21a and 21b that communicate with metering chambers 5 and 6, respectively, which are partitioned by metering membrane 4, and outlet 20 that communicates with outflow port 3. and a sliding switching valve 2 which can alternately rotate back and forth between two limit positions in conjunction with a metering membrane to alternately communicate the inlets and outlets 21a and 21b with the outlet 20 in cooperation with the valve seat.
3, the valve seat 19a has an outlet 20 in the center with respect to the direction of movement of the switching valve 23, and openings 21a and 21b in the center of the valve seat 19a.
The switching valve 23 is characterized in that the switching valve 23 is shaped so as to close the outlet 20 at the central position and open the inlet/outlet 21a and 21b.

RO-2 Effect When the sliding switching valve is located at one limit position and the inlet/outlet 21a communicates with the outlet 20, gas flows into the metering chamber 6 from the inlet/outlet 21b, and from the metering chamber 5 through the inlet/outlet 21a and the outlet. It flows out to the outlet 3 via 20. When the switching valve 3 is switched to the other limit position in conjunction with the movement of the metering membrane 4, gas enters the metering chamber 5 through the inlet/outlet 21a, and from the metering chamber 6 into the inlet/outlet 21b.
It flows out to the outlet 3 via the outlet 20.

During normal operation, the switching valve 23 reciprocates alternately between the two limit positions in this way, so it does not stop at the central position. When you want to shut off the gas in an emergency, etc., if you stop the switching valve 23 in the center position,
The outlet 20 is closed, leaving the entrances and exits 21a and 21b open. Therefore, the pressure in the metering chambers 5 and 6 communicating with the inlet/outlet ports 21a and 21b, respectively, is the same, and no differential pressure is applied to the metering membrane. A differential pressure that presses the switching valve 23 toward the valve seat side acts on the switching valve 23.

RO-3 Embodiment In Figures 1 and 2, 1 is the case body;
It has a gas inlet 2 and an outlet 3. 4 is a metering membrane that divides the metering chamber into a front metering chamber 5 and a rear metering chamber 6, and 7 is a wing shaft, which is supported by the main case pair so as to be rotatable back and forth. Reference numeral 8 denotes a blade that connects the blade shaft 7 and the metering membrane 4 , one end of which is fixed to the blade shaft 7 and the other end connected to the center of the metering membrane 4 . The measuring chamber 5 is indicated by the symbol 5 in FIG. 1, but the measuring chamber 6
does not appear in the drawing. Reference numeral 9 denotes a driving magnet fixed to the upper end of the blade shaft 7 and having a cylindrical outer diameter, and the outer periphery thereof is magnetized into four poles. 10 is a cylindrical driven magnet arranged concentrically with the driving magnet so as to surround the driving magnet 9;
It has four magnetic poles on its inner circumference. 11 and 12
is a member for rotatably supporting the driven magnet 10 around the blade shaft 7, and is bonded to the driven magnet 12 and loosely engaged with the blade shaft 7. Reference numeral 13 denotes a mounting screw for mounting the member 11 so that it does not come off the wing shaft 7. 14 has one end attached to member 11 with screws 15 and 1.
With the arm fixed at 6, pin 1 is attached to the other end (left end)
7 is fixed with a screw 18. The pin 17 is fixed in a groove 14a provided in the arm 14 so that the distance from the wing shaft 7, which is the center of rotation of the arm 14, can be adjusted.

19 is a distribution chamber provided at the top of the case body 1;
It has a valve seat 19a on its upper surface, and this valve seat has an outlet 20 in the center and an outlet 21 in front and behind it.
a, 21b (see Figure 3).

A sliding switching valve 23 is rotatable around a machine screw 22 fixed to the distribution chamber 19, and slides in the front and back direction on the upper surface of the valve seat 19a to selectively communicate the outlet 20 with the inlet/outlet 21a or 21b. do. This communication takes place via a passage 23a provided in the switching valve. The switching valve 23 has parallel parts 23b and 23c in its upper part, and the pin 17 is fitted and secured between the parts.

Stoppers 24a and 24b determine the limit position of the switching valve 23, and are fixedly installed in holes 26 and 27, respectively, provided in the distribution chamber 19 shown in FIG.

Note that 28 in FIG. 3 is a screw hole for fixing the machine screw 22.

29 is a magnet adhered to the left side surface of the switching valve 22.

The outlet 20 of the valve seat 19a communicates with the outlet 3 through a passage 30 in the case body, and the outlets 21a and 21b communicate with metering chambers 5 and 6 (not shown), respectively. Reference numeral 31 denotes an upper case which is overlapped and screwed onto the upper part of the case body 1 via a gasket, and houses the magnets 9 and 10, the switching valve 23, etc., and also has an upper chamber 32 communicating with the inflow port 2. is forming.

Inside the upper chamber 32, a plunger 33 and an electromagnet for operating the plunger 33 are also provided. This electromagnet has a yoke 34 and a coil 35.
Magnets 36 and 37 are attached to the. 38 is a suction plate, which is always urged to the right by a spring 39. 39a is a compression spring provided between the suction plate 38 and the plunger 33, and 40 is a stopper. Note that the electromagnet is fixed by attaching a yoke 34 to the upper part of the case body 1. In addition, plunger 33
The tip (right end) is pointed in the shape of a cannonball.

Reference numeral 41 denotes an L-shaped reset member, which is attached to the upper case 31 so as to be rotatable around a machine screw 42. When the cap 43 is removed and the push button 44 is pushed in against the spring 45, the L-shaped reset member is pushed through the rod 46 and the pin 47, and is rotated around the machine screw 42 as shown in FIG. By rotating clockwise and pushing the suction plate 38 to the left, the plunger can be restored to the illustrated position. As shown in FIGS. 4A, B, and C, the switching valve 23 has a V-shaped surface 23d at the upper left end. Further, a sliding surface 23e is formed on the lower surface of the switching valve surrounding the passage 23a, and this sliding surface 23e is formed on the lower surface of the valve seat 19a.
slides on the top surface of the

FIG. 5 shows a switching valve 2 on the valve seat 19a of the distribution chamber 19.
The state shown is that the switching valve 2 is mounted.
3 is located at the center after the front and rear limit positions, and at this time, the sliding surface on the lower surface of the switching valve 23 rests around the outlet 20 of the valve seat as shown in FIG. 6C. The exit 20 is closed. 6th
The figure shows an outlet 20 of the valve seat 19a in the distribution chamber 19,
This is a diagram illustrating the positional relationship between the inlet/outlet ports 21a, 21b and the switching valve 23. The switching valve is shown as viewed from the bottom surface superimposed on the valve seat for easy understanding. In Figure A, when the switching valve is at the rear limit position, the inlet/outlet 21b communicating with the measuring chamber 6 (not shown) communicates with the outlet 20 via the passage 23a of the switching valve 23, and the switching valve 23 is in communication with the outlet 20 (not shown). The entrance/exit 21a communicating with the metering chamber 5 is shown communicating with the upper chamber 32 without being influenced by the switching valve 23. Also, in FIG. B, when the switching valve 23 is at the forward limit position, the inlet/outlet 21a communicating with the measuring chamber 5 communicates with the outlet 20 via the passage 23a of the switching valve 23, and with the measuring chamber 6. The inlet/outlet 21a has a switching valve 23.
It shows a state in which it communicates with the upper chamber 32 without being affected by.

The operation of the above embodiment will be explained using FIGS. 7A, B, and C. In Figures A, B, and C, the left-hand diagram is a diagram explaining the position of the switching valve 23 and the gas flow at that time, and the right-hand diagram is a diagram explaining the position of the switching valve 23 and the flow of gas at that time, and the diagram on the right is a diagram explaining the position of the switching valve 23 and the flow of gas at that time.
The positional relationship and the position of the arm 14 are shown. As shown in FIG. 7A, when the switching valve 23 is at the forward limit position (at this time, the front edge of the switching valve 23 is in contact with the stopper 24a in FIG. 2, and the force of the driven magnet is against the stopper 24a). ), the driven magnet 10 is in the position shown and the arm 14 is aligned with the center line X-X.
It is at the illustrated position a rotated forward by an angle θ from . In this state, gas enters the metering chamber 6 through the inlet/outlet 21b, the gas in the metering chamber 5 flows through the inlet/outlet 21a, the passage 23a, and the outlet 20, and the metering membrane 4 moves forward. Along with this movement, the drive magnet 9 rotates counterclockwise.

At this time, the switching valve 23 is moved to the stopper 24 in FIG.
The arm 14 is stopped in the position shown in the figure. The metering membrane moves forward, and the driving magnet 9 rotates by an angle of slightly more than 2θ from the position shown in Figure A. Figure B shows the state in which the driving magnet 9 has rotated to a position where it just opposes the magnetic pole of the driven magnet. It is. At this time, there is still room for the metering membrane 4 to move forward. The metering membrane 4 moves forward a little more,
When the magnetic pole of the driving magnet crosses the position of the magnetic pole of the opposing driven magnet, the rotational force that the driven magnet had been receiving until now due to the magnetic force of both magnets is reversed from counterclockwise to clockwise, so the driven magnet instantly changes 2θ. is rotated clockwise by a snap action, and the switching valve 23 is also moved rearward, so that the rear edge reaches the stopper 24b shown in Fig. 2.
It stops when it hits. Then, the state shown in FIG. 7C, in which the magnet is pressed against the stopper 24b by the magnetic force of both magnets, is reached.
Since the switching valve 23 now switches the direction of gas flow to the metering chambers 5 and 6, the direction of the metering membrane 4 is reversed so that it moves rearward, and the drive magnet 9 also reverses its direction of rotation and rotates clockwise. It begins to rotate in the direction. Then, when the drive magnet 9 rotates by an angle of a little more than 2θ from the state shown in FIG.
The magnetic pole of the driving magnet that opposes the magnetic pole of the driven magnet rotates clockwise beyond the position of the opposing magnetic pole. Then, the driven magnet instantaneously reverses and rotates counterclockwise by 2θ, thereby switching the switching valve 23 to the state shown in FIG.

In this way, the metering membrane 4
moves back and forth to measure the gas. The switching valve 23 swings back and forth each time. A flow rate signal transmitter 48 as shown in FIG. Close to or away from the switch,
The reed switch turns on and off, sending out electrical pulses as many times as the metering membrane is actuated.

When an abnormality is sensed by a gas leak alarm or an earthquake sensor (seismic sensor) (not shown), an abnormal signal is transmitted from the outside to the gas meter, and a one-shot current is passed through the electromagnet coil 35 in Fig. 2. , up until now, the suction plate 38 was pressed against the spring 39 and the yoke 3
A magnetic field in the opposite direction to the magnetic field of the magnets 36 and 37 that was attracted to the yoke 4 is generated by the current flowing through the coil, and the attraction plate moves away from the yoke 34 to the right in FIG. Then, the plunger 33 also moves together, and the bullet-shaped tip at the right end pushes the engaging portion of the switching valve 23, that is, the V-shaped surface 23d, so that the switching valve 23 has the plunger 33 contacting the center of the V-shaped surface 23d. be moved to a position where they touch each other. That is, the switching valve 23 moves to the central position shown in FIGS. 5 and 6C, and is held at this position by the spring 39. In addition, suction plate 3
8 is pushed to the right by the spring 39 together with the plunger 33 until it hits the stopper 40, and after the suction plate hits the stopper 40, the spring 39a
presses the plunger 33 against the V-shaped surface 23d. When the plunger 33 holds the switching valve 23 in the center position in this way, the outlet 20 of the valve seat 19a is closed by the switching valve 23, and gas pressure is applied to the switching valve 23 from above, so the switching valve 23 closes the outlet 20. Close securely.

In this state, the gas pressure in the upper chamber 32, that is, the gas pressure from the inlet enters both the metering chambers 5 and 6 from the ports 21a and 21b, and the pressure on both sides of the metering membrane 4 becomes the same, so there is no force to move the metering membrane. Does not occur.

In this way, the switching valve 23 is connected to the central outlet 20.
In order to restore the state in which the gas flow is cut off by facing the gas flow after the abnormal signal disappears, press the push button 44 and rotate the reset member 41 as described above. Let's do it.

C. Effects of the invention There is no need for a valve seat and valve body exclusively for shutoff, and in addition, no unreasonable force is generated in the switching drive mechanism when shutting off.

Therefore, a gas meter with a shutoff device having a simple structure and low cost can be realized.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention; Fig. 1 is a longitudinal front view, Fig. 2 is a front view of the upper case cut horizontally, and Fig. 3 A and B are a top view of the distribution chamber 19 and B-B.
4A, B, and C are top views, longitudinal sectional views, and bottom views of the switching valve 23; FIG. 5 is a top view of the switching valve mounted on the distribution chamber; and FIGS. 6A and B. , C are top views for explaining different positions of the switching valve with respect to the valve seat of the distribution chamber, and FIGS. 7A, B, and C are diagrams for explaining the operation of the switching valve, the driving magnet, the driven magnet, etc. DESCRIPTION OF SYMBOLS 1... Case body, 2... Inflow port, 3... Outlet port, 4... Metering membrane, 5, 6... Metering chamber, 9... Drive magnet, 10... Driven magnet, 19a... Valve seat, 2
0...Exit, 21a, 21b...Entrance/exit, 23...
...Switching valve.

Claims (1)

[Scope of utility model registration request] A valve seat 19a has inlets 21a and 21b communicating with the metering chambers 5 and 6 separated by the metering membrane 4, and an outlet 20 communicating with the outlet 3; , a sliding switching valve 23 that can alternately reciprocate between two limit positions in conjunction with the metering membrane 4 to alternately communicate with the outlet 20;
The valve seat 19a is located at the outlet 2 with respect to the moving direction of the switching valve 23.
0 is arranged in the center and on both sides of the outlet 20, which are inlets 21a and 21b, and the switching valve 23 is shaped to close the outlet 20 at the center position and open the inlets 21a and 21b. , and a plunger 33 operated by an electromagnet that moves the switching valve 23 to a central position and holds it at this position is provided, and the switching valve 23 is provided with an engaging portion that engages with the plunger 33 when the plunger 33 advances. A gas meter with a shutoff device characterized by: